1. Field of the Invention
The present invention relates to computer systems for documenting human pain and pain intensity, and more particularly to computer pain assessment techniques or tools.
2. Description of Related Art
Bodily pain is a rather subjective, complex phenomenon consisting of a sensorial perception, sometimes revealing a potential or real tissular lesion, and the affective response, such as crying or verbal outburst, provoked by this sensorial perception. As bodily pain sensation is also psychic, objective evaluation thereof is difficult.
Pain evaluation during clinical examination of patients includes evaluation of pain sensitivity and is generally performed by means of palpation of skin or underlying tissues (for example muscles), or by means of other more or less reliable methods. Both the response to manual palpation and evaluation of pain sensitivity from such response is complex and often unreliable, as well as, verbal reports of the patient which are generally unreliable since such reports depend on the patient's recollection of pain, and since bodily pain may widely vary within the same day and from one day to another. It is well known that retrospective symptom data including pain are notoriously inaccurate.
Clinical methods include well known paper pain mapping of the pain area and visual analogue scale of the pain intensity (PPM-VAS). In these methods, patients are presented with paper images of the anterior and posterior of the human body and a finite length scale on paper for indication of no pain or superficial pain at one end to extreme pain at the other end, perhaps on a scale of one to ten or zero to one hundred. The patient colors or shades in the entire area where the pain occurs.
Paper pain mapping includes multiple categories of similar pain words from which the patient checks his or her particular pain associated with the area identified on the drawing of a human anterior and posterior. With most paper pain mapping using various symbols of shading, such as a series of x x x x or o o o o or ^ ^ ^ ^, do not allow for several different type pains in the same area of the body. Also, the patient may mark the frequency of recurrence of the pain. Patients with extensive pain areas to shade, such task, using mapping symbols, is tedious and time consuming. If the human body replica is too small, the patient may not be able to shade the exact area of pain.
Using the paper pain mapping and the visual analog scale of intensity it is difficult, if not impossible, to quantify changes in pain perception partly because the area of pain as mapped and the intensity on the visual analog scale are not correlatable.
Lavigne et al., U.S. Pat. No. 5,533,514 describes an algometer system where a representation of a patient's body is displayed on a computer screen and one or more points are marked for pain sensitivity measurement, then a pressure algometer applies pressure at the selected points to the patient's body until the patient perceives the pain threshold of pain (tolerance) and pushes a stop button which holds the pressure applied. Also, the patient selects a pain intensity value on a visual analog scale. These values are stored in the patient's records.
Lavigne et al., in a later U.S. Pat. No. 5,592,947, discloses improvements over the earlier patent that provides a method and an algometer designed for facilitating intensification of the applied pressure at a constant adjustable rate.
The foregoing patents to Lavigne et al., provide for pressure-pain threshold data where palpation examination is more of a sensitivity to pain analysis.
It appears from the early oral and palpation examinations and even paper pain mapping and visual analog scales system, which are heavily subjective, that there is a need for less subjective and more objective clinical inputs from the patient concerning when, where, what and how his or her sensorial perception of pain occurs.